The broad objective of the present research proposal is to study the cells of the female reproductive system during various phases of the reproductive process by use of techniques of light and electron microscopy (such as electron cytochemistry and radioautography), freeze fracture and culturing methods. The investigation is an attempt to learn more about the submicroscopic organization, spatial arrangement, and chemical composition of the various regularly occurring cytoplasmic constituents of this highly specialized protoplasm. The ultimate goal of this research proposal is the correlation of the submicroscopic feature of cells of the mammalian reproductive system with the reproductive process. BIBLIOGRAPHIC REFERENCES: Ducibella, T. and Anderson, E. 1975. Cell Shape and membrane changes in the 8 cell mouse embryo: prerequisites for the morphogenesis of the blastocyst. Devel. Biol. 47:45-58. Anderson, E., G. Lee, R. Letourneau, D.F. Albertini and S.M. Meller. 1976. Cytological observations of the ovarian epithelium in mammals during the reproductive cycle. J. Morph.